/Engine/Source/Runtime/Engine/Public/Net/RepLayout.h
Called to indicate that the object referenced by theFNetworkGUIDis no longer mapped. This can happen if the Object was destroyed, if its level was streamed out, or for any other reason that may cause the Server (or client) to no longer be able to properly reference the object. Note, it's possible the object may become valid again later.
bool MoveMappedObjectToUnmapped ( [FReceivingRepState](API\Runtime\Engine\Net\FReceivingRepState) *__restrict RepState, struct [FNetDeltaSerializeInfo](API\Runtime\CoreUObject\UObject\FNetDeltaSerializeInfo) & Params, const [FNetworkGUID](API\Runtime\Core\Misc\FNetworkGUID) & GUID ) const